Method and system for air conditioning remote control in car

ABSTRACT

Disclosed are a system and a method for air conditioning remote control in a car, in which air conditioning is carried out at various levels depending on situations determined on based on a comparison between the time required for a user to arrive at the car and the operation time of an air conditioner required to change an indoor temperature of the car to a preset temperature upon receiving the request, whereby energy efficiency can be enhanced.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority to Korean PatentApplication No. 10-2016-0156575, filed on Nov. 23, 2016, the entirecontents of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

The present disclosure relates generally to a system and method for airconditioning remote control in a car, and more particularly, to a systemand method for air conditioning remote control in a car, whereby airconditioning is carried out at various levels depending on differentsituations to enhance energy efficiency.

2. Description of the Related Art

Remote air conditioning systems allow a user to remotely control the airconditioning of a car prior to entering the car. Thus, even in the hotsummer or cold winter, a user can feel comfortable when getting into thepre-conditioned car.

In this regard, a user (e.g., a car owner) remotely orders a controlsystem in the car to make the conditions in the car comfortable beforehe or she enters inside. Immediately after receiving the order, aconventional air conditioning remote control system transmits the orderand conducts air conditioning to reach a desired temperature. However,because a conventional system conducts air conditioning as soon as itreceives the order without taking into account the time that the usergets into the car or the prospect of energy efficiency, the airconditioning may be performed to an extent far greater than what isactually required by the user.

Excessive air conditioning decreases fuel efficiency, resulting inenvironmental pollution. Moreover, an electric vehicle suffers asignificant reduction in travel range due to the limited capacity of itshigh-pressure battery.

Accordingly, there is a need for a solution by which air conditioningcan be remotely controlled so as to minimize the expense associated withenergy consumption.

The description provided above is solely provided to assist inunderstanding the background of the present disclosure, and should notbe construed as being included in the related art known by those skilledin the art.

SUMMARY

The present disclosure has been made in an effort to solve the aboveproblems. An object of the present disclosure is to provide a system andmethod for air conditioning remote control in a car, in which airconditioning is carried out at various levels depending on situationsdetermined based on a comparison between the time required for a user toarrive at the car and the required operation time of the airconditioner, in consideration of a preset temperature upon receipt ofthe request for air conditioning remote control. As a result, energyefficiency of the system can be enhanced.

In accordance with embodiments of the present disclosure, a system forair conditioning remote control in a car includes: a user terminal of auser configured to perform wireless communication; an air conditionerequipped in the car; and a controller configured to control operation ofthe air conditioner and to communicate wirelessly with the userterminal, the controller having functions of: receiving a request forair conditioning remote control from the user terminal, calculating anoperation time of the air conditioner required to change an indoortemperature of the car to a preset temperature upon receiving therequest, calculating a wait time by subtracting the operation time ofthe air conditioner from a time required for the user to arrive at thecar, and operating the air conditioner after the wait time has passedsince receiving the request when the time required for the user toarrive at the car is longer than the operation time of the airconditioner.

The controller may receive the preset temperature from the user terminaland calculates the operation time of the air conditioner based on thereceived preset temperature.

The controller may calculate an air conditioning load based on adifference between a current temperature and a required temperature uponreceipt of the request and calculate the operation time of the airconditioner based on the calculated air conditioning load.

The controller may calculate an air conditioning load and the operationtime of the air conditioner based on information of the car and adifference between a current temperature and a required temperature uponreceipt of the request.

The information of the car may include a power of the air conditionerand an inner volume of a passenger compartment of the car.

The controller may calculate the time required for the user to arrive atthe car based on data received from the user terminal.

The data received from the user terminal may include data that the userinputs with regard to a time that the user will arrive at the car.

The controller may calculate the time required for the user to arrive atthe car based on a position of the user terminal, a position of the car,and a moving speed of the user.

The controller may operate the air conditioner upon receiving therequest when the time required for the user to arrive at the car isshorter than or equal to a time required to operate the air conditioner.

When the time required for the user to arrive at the car is longer thanthe operation time of the air conditioner, the controller may perform anair blowing mode, in which outdoor air is introduced into an interior ofthe car without operating the air conditioner, during a waiting timebetween a time of receiving the request and a time of commencingoperation of the air conditioner.

The air blowing mode may be performed such that an opening unitproviding a passage from an inside of the car to an outside is openedwhen it is determined that it is not raining.

The air blowing mode may be performed when it is determined that coolingis needed at the indoor temperature of the car higher than an outdoortemperature.

The opening unit may be closed when the air blowing mode is stopped orwhen the air conditioner starts to operate.

The air blowing mode may be performed when it is determined that heatingis needed at the indoor temperature of the car lower than an outdoortemperature.

Also, according to embodiments of the present disclosure, a system forair conditioning remote control in a car includes: a user terminal intowhich a request for air conditioning remote control is input by a user;an air conditioner equipped in the car; a controller configured tocontrol operation of the air conditioner; and a server, provided outsidethe car, having functions of: communicating with the user terminal andthe controller, receiving the request from the user terminal,calculating an operation time of the air conditioner required to changean indoor temperature of the car to a preset temperature upon receivingthe request, calculating a wait time by subtracting the operation timeof the air conditioner from a time required for the user to arrive atthe car, and operating the air conditioner after the wait time haspassed since receiving the request when the time required for the userto arrive at the car is longer than the operation time of the airconditioner.

Further, according to embodiments of the present disclosure, a methodfor air conditioning remote control in a car includes: receiving arequest for air conditioning remote control from a user terminal of auser; calculating an operation time of an air conditioner required tochange an indoor temperature of the car to a preset temperature uponreceiving the request; calculating a wait time by subtracting theoperation time of the air conditioner from a time required for the userto arrive at the car; and operating the air conditioner after the waittime has passed since receiving the request when the time required forthe user to arrive at the car is longer than the operation time of theair conditioner.

The system and method for air conditioning remote control in a car inaccordance with embodiments of the present disclosure can perform airconditioning at various levels depending on situations determined basedon a comparison between the time required for the user (e.g., the carowner, a passenger, etc.) to arrive at the car and the requiredoperation time of an air conditioner in consideration of a presettemperature upon receipt of a request for air conditioning remotecontrol, whereby energy efficiency of the air conditioning system can beenhanced.

The system and method can accurately calculate the time required for auser to arrive at the car, even when he or she does not input the time,by comparing the position of the car with the position data, such asglobal positioning system (GPS) data, of the user.

In addition, by comparing the time required for the user to arrive atthe car with the required operation time of the air conditioner todetermine when to commence operation of the air conditioner, the methodand system can establish a waiting time between the time of receipt of arequest for air conditioning remote control and the time to startoperating the air conditioner to eliminate unnecessary energyconsumption, with the consequent improvement of energy efficiency.

Further, an air blowing mode, whereby outdoor air is blown into thecar's interior, is selectively carried out depending on a result ofcomparing indoor and outdoor temperatures to determine the need forheating or cooling, so that the indoor temperature can be adjustedwithout operating the air conditioner, resulting in enhanced energyefficiency.

In the case where the time required for the user to arrive at the car isshorter than or the same as the required air conditioner operation time,the air conditioner is operated as soon as a communications unitreceives a request for air conditioning remote control, which results inoptimal fuel consumption and high energy efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic diagram showing the organization of a system forair conditioning remote control in a car in accordance with embodimentsof the present disclosure; and

FIG. 2 is a flow chart showing a method for air conditioning remotecontrol in a car in accordance with embodiments of the presentdisclosure.

It should be understood that the above-referenced drawings are notnecessarily to scale, presenting a somewhat simplified representation ofvarious preferred features illustrative of the basic principles of thedisclosure. The specific design features of the present disclosure,including, for example, specific dimensions, orientations, locations,and shapes, will be determined in part by the particular intendedapplication and use environment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. As those skilled inthe art would realize, the described embodiments may be modified invarious different ways, all without departing from the spirit or scopeof the present disclosure. Further, throughout the specification, likereference numerals refer to like elements.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It is understood that the term “car,” “vehicle,” “vehicular,” or othersimilar term as used herein is inclusive of motor vehicles in generalsuch as passenger automobiles including sports utility vehicles (SUV),buses, trucks, various commercial vehicles, watercraft including avariety of boats and ships, aircraft, and the like, and includes hybridvehicles, electric vehicles, plug-in hybrid electric vehicles,hydrogen-powered vehicles and other alternative fuel vehicles (e.g.,fuels derived from resources other than petroleum). As referred toherein, a hybrid vehicle is a vehicle that has two or more sources ofpower, for example both gasoline-powered and electric-powered vehicles.

Additionally, it is understood that one or more of the below methods, oraspects thereof, may be executed by at least one controller. The term“controller” may refer to a hardware device that includes a memory and aprocessor. The memory is configured to store program instructions, andthe processor is specifically programmed to execute the programinstructions to perform one or more processes which are describedfurther below. Moreover, it is understood that the below methods may beexecuted by an apparatus comprising the controller in conjunction withone or more other components, as would be appreciated by a person ofordinary skill in the art.

Furthermore, the controller of the present disclosure may be embodied asnon-transitory computer readable media containing executable programinstructions executed by a processor, controller or the like. Examplesof the computer readable mediums include, but are not limited to, ROM,RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives,smart cards and optical data storage devices. The computer readablerecording medium can also be distributed throughout a computer networkso that the program instructions are stored and executed in adistributed fashion, e.g., by a telematics server or a Controller AreaNetwork (CAN).

Below, a description will be given of a system and a method for airconditioning remote control in a car according to embodiments of thepresent disclosure, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the organization of a system forair conditioning remote control in a car in accordance with embodimentsof the present disclosure. FIG. 2 is a flow chart showing a method forair conditioning remote control in a car in accordance with embodimentsof the present disclosure.

Referring first to FIG. 1, an organization of a system for airconditioning remote control in a car in accordance with embodiments ofthe present disclosure is schematically illustrated. As shown in FIG. 1,the system for air conditioning remote control in a car in accordancewith embodiments of the present disclosure may is composed of a userterminal 100, a car 300, and a server 500. The car 300 may comprise acontroller 320, an air conditioner 340, an opening unit 360, an outdoortemperature sensor 370, an indoor temperature sensor 380, and a rainsensor 390. The controller 320 may be divided into a processor 322, acommunications unit 324, a storage 326, and a calculation unit 328.

In one embodiment of the present disclosure, the user terminal 100 maybe a device communicating over a network. Examples of the user terminalinclude a personal computer, a UMPC (Ultra Mobile PC), a workstation, anetbook, a PDA (Personal Digital Assistant), a PMP (Portable MultimediaPlayer), a portable computer, a web tablet, a wireless phone, a mobilephone, a smart phone, an e-book, a smart TV, a portable game console, avehicle information system, a navigation system, a 3-dimensionaltelevision receiver, a DMB (Digital Multimedia Broadcasting) TV set, awireless communication device, an electronic device connected to a homenetwork, an electronic device connected to a computer network, and anelectronic device connected to a telematics network. A request forremote air conditioning may be inputted to the user terminal 100 from auser (e.g., a car owner, a passenger, etc.), and the user terminal 100transmits the request to the server 500. Optionally, the request may betransmitted directly to the controller 320 via wireless communication,rather than via the server 500.

In an embodiment of the present disclosure, the calculation unit 328 ofthe controller 320 performs various calculation logic, such ascomparison between an outdoor temperature and an indoor temperature onthe basis of data from the outdoor temperature sensor 370, the indoortemperature sensor 380, and the rain sensor 390.

According to one embodiment, the calculation unit 328 of the controller320 compares the outdoor temperature with an indoor temperature andcalculates the amount of time that it is necessary to operate an airconditioner based on the information from the outdoor temperature sensor370, the indoor temperature sensor 380, and the rain sensor 390. Thecalculation unit 328 can utilize information from the rain sensor 390or, alternatively, a meteorological office instead of the rain sensor390 to determine whether or not it is raining. The storage 326 of thecontroller 320 stores various desired values, measurements, calculatedvalues, etc. The communications unit 324 of the controller 320 receivesa request for air conditioning remote control through the server 500from the user terminal 100 (or directly from the user terminal). Theprocessor 322 of the controller orders both the air conditioner 340 andthe opening unit 360 to operate.

In one embodiment of the present disclosure, the opening unit 360 of thecar 300 includes a sunroof and car windows and may be closed or openeddepending on whether or not it is raining, as determined by the rainsensor 390, for example. If the opening unit is opened, the sunroof maybe fully opened while the car windows may be partially opened in orderto prevent the car or items present in the car from being stolen. Theopening unit may include various means connecting the inside of the carto the outside, in addition to windows and a sunroof.

FIG. 2 is a flow chart showing a method for air conditioning remotecontrol in a car in accordance with embodiments of the presentdisclosure.

As shown in FIG. 2, the method comprises receiving a request for airconditioning remote control from a user terminal 100 (S100); predictinga time at which the user will arrive at the car 300 (S200); calculatingan operation time of an air conditioner 340 required to make an indoortemperature of the car 300 reach a preset temperature (S300); comparingthe operation time of the air conditioner 340 with the time required forthe user to arrive at the car 300 (S400); comparing an outdoortemperature with the indoor temperature (S420); determining whether theinterior of the car is heated or cooled (S440); and sending air to theinterior of the car (S500).

In the step of receiving a request for air conditioning remote controlfrom a user terminal, a user, e.g., a car owner or passenger, uses theuser terminal to make a request for air conditioning remote control.When making the request, the user may input data. According to oneembodiment of the present disclosure, the input data may include adesired temperature and the estimated time of arrival or position dataof the user terminal 100. In this regard, the user may or may notdirectly input the estimated time of arrival or the position data of theuser terminal 100.

Upon predicting the time required for the user to arrive at the car(S200), account is taken of the following two cases: whether or not datais input directly by the user. If the directly input data is theestimated time of arrival, it may be used without change. On the otherhand, if the data pertains to position, the time required for the userto arrive at the car is derived on the basis of the estimated time ofarrival, calculated by the server from the position data. Alternatively,when the user does not directly input data, the server 500 derives theestimated time of arrival in consideration of the average human walkingspeed on the basis of the GPS position data of both the car 100 and theuser terminal 100, and sends the estimated time of arrival to thecommunications unit 324 of the car 300.

In the step of calculating the operation time of an air conditioner 340(S300), the controller can derive an air conditioning load inconsideration of various factors including the difference between acurrent temperature and a required temperature, the power of the airconditioner, and the inner volume of the passenger compartment of thecar upon receipt of air conditioning remote control. The operation timeof the air conditioner is calculated based on the derived airconditioning load. For example, delta T, which is the difference betweenthe current temperature and a preset temperature, and the inner volumeof the passenger compartment of the car are used to derive an airconditioning load, which is then divided by the power of the airconditioner to calculate the time for which it is required to operatethe air conditioner.

For the step of comparing the operation time of the air conditioner 340with the time required for the user to arrive at the car 300 (S400),account is taken of the following two cases: whether or not the timerequired for the user to arrive at the car is longer than the time forwhich it is required to operate the air conditioner 340. First, in thecase where the time required for the user to arrive at the car isshorter than or the same as the time for which it is required to operatethe air conditioner 340, the air conditioner 340 is operated as soon asthe communications unit receives a request for air conditioning remotecontrol (S600).

On the other hand, if the time required for the user to arrive at thecar is longer than the time for which it is required to operate the airconditioner 340, the air conditioner 340 is operated after an amount oftime (alternatively referred to herein as a “wait time”) has passedsince the time of receipt of the request for air conditioning remotecontrol. The wait time may be calculated by subtracting the requiredoperation time from the time of arrival. By way of example, assume thatthe communications unit receives a request for air conditioning remotecontrol at 1:00 pm, that the required air conditioner 340 operation timeis 10 min, and that it will take 30 min for the user to arrive at thecar. The air conditioner starts to operate at 1:20 pm, because therequired operation time (10 min) is subtracted from the time it willtake for the user to arrive (30 min). From the starting time, the airconditioner 340 operates for 10 min.

In one embodiment of the present disclosure, if the time required forthe user to arrive at the car is longer than the required airconditioner 340 operation time, either the server 500 or the controller320 may order that the air conditioner 340 be operated after the passageof an amount of time (i.e., “wait time”), obtained by subtracting therequired operation time from the time of arrival, starting at the timeof receipt of a request for air conditioning remote control.

During the wait time between the time of receipt of a request for airconditioning remote control and the time of commencement of operation ofthe air conditioner 340, the controller 320 selectively performs an airblowing mode, in which outdoor air is introduced into the interior ofthe car without operating the air conditioner 340, according to theresult of comparing indoor and outdoor temperatures or depending onwhether heating or cooling is required (S420, S440, S460).

The air blowing mode is carried out when it is determined that coolingis needed at an indoor temperature higher than an outdoor temperature orthat heating is needed at an indoor temperature lower than an outdoortemperature. For the case where cooling is needed at an indoortemperature higher than an outdoor temperature, the air blowing mode iscarried out in a manner such that the opening unit 360 is opened if itis determined that it is not raining after an examination is madethrough the rain sensor 390 or from weather information to see whetheror not it is raining. The opening unit remains open until there is nodifference between the indoor temperature and the outdoor temperature.Thereafter, the opening unit is closed, and the controller 320 comparesthe time required for the user to arrive at the car with the requiredoperation time of the air conditioner to determine whether or not tooperate the air conditioner 340.

On the other hand, when it is raining, the controller 320 cannot openthe opening unit 360. Accordingly, the air conditioner introducesoutdoor air into the interior of the car to adjust the indoortemperature.

For example, when the indoor temperature of a car is 50° C. on a summerday of 30° C., the air blowing mode is carried out, ahead of theoperation of the air conditioner 340, if cooling is required. Here, inthe air blowing mode, a sunroof and car windows may be opened, or ablower may be operated depending on whether or not it is raining.

On a winter day of −5° C., when an indoor temperature is 10° C., the airconditioner 340 is simply operated if heating is required. The reasonwhy the air blowing mode is not conducted is to prevent inefficient fuelconsumption. If the air blowing mode is conducted, chilly outdoor air isintroduced into the interior of the car and thus lowers the indoortemperature, which requires additional air conditioning, resulting inincreased fuel consumption. In general, the indoor temperature of a caris higher than the outdoor temperature in a closed space, regardless ofthe season.

In contrast, when heating is needed in the state in which the indoortemperature is lower than the outdoor temperature, an air blowing modeis conducted to adjust the indoor temperature, during which the timerequired for the user to arrive at the car is compared with the requiredair conditioner 340 operation time to determine whether to operate theair conditioner 340. Upon the operation of the air conditioner 340, apower consumer other than the air conditioner may be electricallyblocked or isolated. The power consumer may include an air conditioningdisplay.

As described hitherto, the system and the method for air conditioningremote control in accordance with embodiments of the present disclosurecan accurately calculate the time required for a user, e.g., a carowner, a passenger, or the like, to arrive at the car, even when he orshe does not input the time, by comparing the position of the car withthe GPS position data of the user.

In addition, by comparing the time required for the user to arrive atthe car with the required operation time of the air conditioner todetermine when to commence operation of the air conditioner, the methodand system can establish a wait time between the time of receipt of arequest for air conditioning remote control and the time to startoperating the air conditioner to eliminate unnecessary energyconsumption, with the consequent improvement of energy efficiency.

Further, the air blowing mode is selectively carried out depending on acomparison of indoor and outdoor temperatures to determine the need forheating or cooling, so that the indoor temperature can be adjustedwithout operating the air conditioner, resulting in enhanced energyefficiency.

In the case where the time required for the user to arrive at the car isshorter than or equal to the required air conditioner operation timewhen comparing the time required for the user to arrive at the car withthe required operation time of the air conditioner, the air conditioneris operated as soon as the communications unit receives a request forair conditioning remote control, which results in optimal fuelconsumption and high energy efficiency.

Although embodiments of the present disclosure have been described abovefor illustrative purposes, those skilled in the art will appreciate thatvarious modifications, additions and substitutions are possible, withoutdeparting from the scope and spirit of the disclosure as disclosed inthe accompanying claims.

What is claimed is:
 1. A system for air conditioning remote control in acar, the system comprising: an air conditioner equipped in the car; anda controller configured to control operation of the air conditioner andto communicate wirelessly with the user terminal, the controller havingfunctions of: receiving a request for air conditioning remote controlfrom the user terminal, calculating an operation time of the airconditioner required to change an indoor temperature of the car to apreset temperature upon receiving the request, calculating a wait timeby subtracting the operation time of the air conditioner from a timerequired for the user to arrive at the car, and operating the airconditioner after the wait time has passed since receiving the requestwhen the time required for the user to arrive at the car is longer thanthe operation time of the air conditioner.
 2. The system of claim 1,wherein the controller receives the preset temperature from the userterminal and calculates the operation time of the air conditioner basedon the received preset temperature.
 3. The system of claim 1, whereinthe controller calculates an air conditioning load based on a differencebetween a current temperature and a required temperature upon receipt ofthe request and calculates the operation time of the air conditionerbased on the calculated air conditioning load.
 4. The system of claim 1,wherein the controller calculates an air conditioning load and theoperation time of the air conditioner based on information of the carand a difference between a current temperature and a requiredtemperature upon receipt of the request.
 5. The system of claim 4,wherein the information of the car includes a power of the airconditioner and an inner volume of a passenger compartment of the car.6. The system of claim 1, wherein the controller calculates the timerequired for the user to arrive at the car based on data received fromthe user terminal.
 7. The system of claim 6, wherein the data receivedfrom the user terminal includes data that the user inputs with regard toa time that the user will arrive at the car.
 8. The system of claim 1,wherein the controller calculates the time required for the user toarrive at the car based on a position of the user terminal, a positionof the car, and a moving speed of the user.
 9. The system of claim 1,wherein the controller operates the air conditioner upon receiving therequest when the time required for the user to arrive at the car isshorter than or equal to a time required to operate the air conditioner.10. The system of claim 1, wherein, when the time required for the userto arrive at the car is longer than the operation time of the airconditioner, the controller performs an air blowing mode, in whichoutdoor air is introduced into an interior of the car without operatingthe air conditioner, during a waiting time between a time of receivingthe request and a time of commencing operation of the air conditioner.11. The system of claim 10, wherein the air blowing mode is performedwhen it is determined that cooling is needed at the indoor temperatureof the car higher than an outdoor temperature.
 12. The system of claim10, wherein the air blowing mode is performed such that an opening unitproviding a passage from an inside of the car to an outside is openedwhen it is determined that it is not raining.
 13. The system of claim12, wherein the opening unit is closed when the air blowing mode isstopped or when the air conditioner starts to operate.
 14. The system ofclaim 10, wherein the air blowing mode is performed when it isdetermined that heating is needed at the indoor temperature of the carlower than an outdoor temperature.
 15. A system for air conditioningremote control in a car, a system comprising: an air conditionerequipped in the car; a controller configured to control operation of theair conditioner; and a server, provided outside the car, havingfunctions of: communicating with the user terminal and the controller,receiving the request from the user terminal, calculating an operationtime of the air conditioner required to change an indoor temperature ofthe car to a preset temperature upon receiving the request, calculatinga wait time by subtracting the operation time of the air conditionerfrom a time required for the user to arrive at the car, and operatingthe air conditioner after the wait time has passed since receiving therequest when the time required for the user to arrive at the car islonger than the operation time of the air conditioner.
 16. A method forair conditioning remote control in a car, the method comprising:receiving a request for air conditioning remote control from a userterminal of a user; calculating an operation time of an air conditionerrequired to change an indoor temperature of the car to a presettemperature upon receiving the request; calculating a wait time bysubtracting the operation time of the air conditioner from a timerequired for the user to arrive at the car; and operating the airconditioner after the wait time has passed since receiving the requestwhen the time required for the user to arrive at the car is longer thanthe operation time of the air conditioner.